Welcome to the NIST Chemistry WebBook

Thermochemical data for over 7000 organic and small inorganic
compounds:

Enthalpy of formation

Enthalpy of combustion

Heat capacity

Entropy

Phase transition enthalpies and temperatures

Vapor pressure

Reaction thermochemistry data for over 8000 reactions.

Enthalpy of reaction

Free energy of reaction

IR spectra for over 16,000 compounds.

Mass spectra for over 33,000 compounds.

UV/Vis spectra for over 1600 compounds.

Gas chromatography data for over 27,000 compounds.

Electronic and vibrational spectra for over 5000 compounds.

Constants of diatomic molecules (spectroscopic data) for over 600
compounds.

Ion energetics data for over 16,000 compounds:

Ionization energy

Appearance energy

Electron affinity

Proton affinity

Gas basicity

Cluster ion binding energies

Thermophysical property data for 74 fluids:

Density, specific volume

Heat capacity at constant pressure (Cp)

Heat capacity at constant volume (Cv)

Enthalpy

Internal energy

Entropy

Viscosity

Thermal conductivity

Joule-Thomson coefficient

Surface tension (saturation curve only)

Sound speed

You can search for data on specific compounds in the Chemistry
WebBook based on name, chemical formula, CAS registry number,
molecular weight, chemical structure, or selected ion energetics
and spectral properties.

NIST reserves the right to charge for access to this database in the future.

The National Institute of Standards and Technology (NIST) uses
its best efforts to deliver a high quality copy of the Database
and to verify that the data contained therein have been selected
on the basis of sound scientific judgment. However, NIST makes
no warranties to that effect, and NIST shall not be liable for
any damage that may result from errors or omissions in the
Database.